Celebrating the 12th Anniversary since Command & Conquer series was born, Electornic Arts has released for free the Gold edition of the first title in this popular series, compatible with Windows XP.
Welcome to the New World Order. A gritty high tech world where the art of electronic intelligence and covert surveillance reigns supreme. Where guerrilla strategies and savage combat are the norm. Build bases, muster forces and dominate your enemies. All for the love of power.

Features:

•Complete control over land and air units; muster forces; build bases; and manage resources
•Over 60 minutes of intense action video and 3-D rendered excitement
•Pick your side: Fight the good fight with the GDI or bring the world to its knees with the Brotherhood of Nod
•Over 35 missions in all
•Digitized speech and adrenaline-pumping music featuring 25 original scores
•Detailed, interweaving storyline
•See four times the battlefield/new screen sidebar
•Smooth scrolling screen
In order for C&C GOLD to run on Windows XP, you will need to burn the ISO image onto a CD with a CD Burner and any “CD Burning Software” or perhaps mount the image with daemon tools. The full game download comprises of 2 ISO images.

Sauerbraten (a.k.a. Cube 2) is a free multiplayer/singleplayer first person shooter, built as a major redesign of the Cube FPS.
Much like the original Cube, the aim of this game is not necessarily to produce the most features & eyecandy possible, but rather to allow map/geometry editing to be done dynamically in-game, to create fun gameplay and an elegant engine.

The engine supporting the game is entirely original in code & design, and its code is Open Source (ZLIB license, read the docs for more on how you can use the engine).
The Sauerbraten game is freeware, you may freely distribute the Sauerbraten archive/installer unmodified on any media. You may re-compress using different archival formats suitable for your OS (i.e. zip/tgz/rpm/deb/dmg), any changes beyond that require my explicit permission.

You may play Sauerbraten for any purpose as long as you don’t blame the author(s) for any damages incurred.
Producing Content
If you want to produce new content with the sauerbraten engine, you have to be aware that the source code may be Open Source, but the game and the media it consist of have their individual licenses and copyrights. This means that you have roughly 3 options:
•You may produce new content for the sauerbraten game, for example as a “custom map” (.ogz/.cfg/textures etc). Contributing to the original game is most welcome, and the most productive way of working with sauerbraten.
•If you want to create your own gameplay beyond what you can do with a map, the best way to do this is as a “mod” (same as above, but with new executable that incorporates your gameplay), that requires an existing install of sauerbraten, and installs only the new files you created in parallel to the existing files.
•If you insist on making a standalone game based on sauerbraten, do realize that only the sourcecode is yours to use freely (if you abide by the ZLIB license (see below)), not the media. You CANNOT simply redistribute the entire sauerbraten package with your modified files, as the majority of game media is not yours to use freely (it is made by many authors with a variety of licences and copyright restrictions). Unless you have explicit permission from the authors, or the readme says explicitly “may be used for any purpose” or similar language, it will be illegal to include in your standalone game based on the sauerbraten engine (you may not assume that just because a file has no explicit license, that it is free of copyright). Therefore, if you wish to produce a standalone game, be prepared to make many of the maps, models, textures, sounds etc from scratch yourself.

In this sense sauerbraten is similar to games like Quake (its code is Open Source, but its media is not), it is a game that is meant to be added to, not copied and used as a template. Sauerbraten is not meant to be a quick game creation kit, it is a game.